Bolster



Oct. 29, 1929. H. w. STERTZBACH BOLSTER Filed Janl1, 1927 2 Sheets-Sheet l Get. 29, 1929.

H. w. STERTZBACH BOLSTER Filed Jan. 11, 1927 2 Sheets-Sheet 2 QAN Ill/III gwuento'a dk$m Patented Oct. 29, 1929 UNITED STATES HARRY w. STERTZBACH, or ooriuivnzus, 0x110," ASSIGFNOR To THEBUCKEYE STEEL PATENT] OFFICE ,CASTINGS COMPANY, on COLUMBUS, OHIO BOLSTER Application filed January 11, 1927. Serial No. 160,434.

the distanceoithe fibre from theneutral surface of the structure; :The usual cross sec tional form of a car truck bolster is that of a hollow rectangle or boxsect'ion, which provides considerable strength with economy of material, and it is evident that the maximum combined stresses occur at the corners. Ac cording to the mentioned theory, the stress along a horizontal transverse line of the bolster under vertical load is uniform but tests show the theoretical stress to be exceeded in the end portions of such line While at the centre the stress is less. It is thepurpose of the present invention to provide a bolster which will be actually stronger with less weight than bolsters of the usual form, and to eliminate the corners on which, in the usual sections, the stresses from the two systems of loads combine to form the maximum. Structures embodying the invention are illustrated in the accompanying drawings and will be hereinafter fully set forth and particularly defined.

In the drawings, Figure 1 is a side elevation of: one form of bolster embodying the invention;

Figure 2 is a transverse section on the line 22 of Fig. 1;

Figures 3, 4 and 5 are sections taken on the I lines 33, 4-4 and 5-5, respectively, of Figure 1;

Figure 6 is a side elevation of a second embodiment of the invention;

Figures 7 and 8 are sections on the lines 77 and 88 respectively of Figure 6;

Figure 9 is a side elevation of an embodiment of the invention difiering in details from the previously mentioned forms;

Figure 10 is a transverse section on the line 10-10 of Figure 9;

Figure 11 is asectionon the line 111l of Figure9;"

Figure 12is a view similarto Figure 10 p but showing a variation inform; a

F i 'ure 13 is a section onzthe lme 14-5-14 of b Figure-14;; s

Fi 'ure 1431s a side elevatlon of an end b l r p I portion oi a bolster oi another form.

The bolster 1 is tapered toward its ,ends I from the centre and,jin*the i'orm shown in Figures -1 to 5, has the usual flat *top web 2' to accommodate attachments andbearings that are usually'necessary Ion the upper side ofthebolster; The bolster also has straight 165 side portions 3 whic'hat-the endsof the bolster extend the full {height thereof iwhereby to maintain the usual bearingarea for the springs and have the proper engagement with the usual form of truck --side"frame. @On the interior of the bolster, however, in itsend -port1on,"arcuate reenforcing r1bs"-?4:- are formed across'the right angles defined by the sidewalls 3cand thekbottom 5, and saidangles ato aregiven as'gradu'allyincreasingarcuate form it i on lines passing toward the center -ofthe bolsterand, atthe region ofthe central 1nternalf'brace 6, strictangularlty ot corners disappeariandthe sidesand bottomare joined by true :curves, rasl at ,7. -The radius of the sion member becomes semi-cylindrical, the

semi-cylindrical crossssectional contour being continued to thecenter :of the bolster on a gradually increasing radius, "as willbe .understoodon reference to F 1g. 2. I

8, like the bolster shown in Figs, l-,to 5, tapers vertically lfromxits center toward its ends; arcuate ribs 11 at the junctions oiiits side so I The bolster 10,1shown in FiguresiG, 7,and

Thisform oiibolster has the internal and nbottomrwalls at its end portion l2and alsolhas the corresponding ribs "13 in itsrupper ward from the end portion'lQ, the :bolster 1 iven :an elliptical cross section as shown '95 portion so thatj'an elliptical cross-sectional a contour is shownibytheribs. [Atagp'ointin- E a V semi-circular while the bottom is flat at its center under the brace 16. To facilitate the mounting of accessories upon the bolster, flattop projections 17 are formed on the sides of the top thereof so that the top or compression member of the bolster willpresent a flat surface, as shown in Figure 8. The curvilinear crosssection of the tension and compression membersof the bolster is continued toward the center of the bolster with the vertical axis of the ellipse gradually increasing until, near the center, the cross section more nearly approaches a circle, the centerbearing surface 18 being formed in a manner similar to the projections 17 In'Figures 9, 10 and 11 is shown a bolster having a tension member 19 which is arcuate in cross section and has a curvatureof substantially constant radius, from end to end, as shown" in Figures 10 and 11. This bolster is of cast steel and at its outer end has a spring seat 20 cast integrally therewith, said. seat presenting a flat-surface to the upper ends of the truck springs and'being reenforced by verticalwebs 21and 22 disposed respectively at the'side edges'of the seat and bolster end and at ooints near the'cente'r thereof. The struc ture shown inFigure' 12 differs from that shownin Figures lOand 11 in that the spring seat 23 is cast separately from the bolster and is interengaged with the bolster end by a lug and socket, shown at 24, the seat having a concave top web 25 to fit against the convex under side of the'bolster end and extend to the top of the same. i c In Figures 13 and 14 is illustrated a construction in'which thebolster is of a builtup tvpe, the tension member 26 having a transverse curvature which is of substantially constant radius throughout the length of the member. Flanges 27 extend along the top edges of the bolster and a top plate 28 is secured upon the flanges, said plate being dished and turned down at its outer end to fit within andbe secured to the end of the tension member. 'The spring seat 29 is preferably a casting interengaged with the bolster end by a lug and socket, shown at 30, and having a concave top web seating'the bolster end.

From the foregoing description, taken in connection with the accompanying drawings, it will be seen that I have provided a novel bolster which will possess all the advantages hereinbefore enumerated asdesirable.

Havingfully described my invention what I claim as new and desire to secure by Letters-Patent, is I 1. A car truck bolster having a tension member of arcuate cross section, and a compression member of inverted channel section fromthe oentral'portion of the bolster outwardly to the ends of the bolster.

. 2. A car truck bolster having a tension member of areuate cross section and a com pression member of inverted channel section from the central portion of the bolster outwardly, the radius of the former gradually uniformly increasing from the end portions of the bolster toward the center thereof, both the tension and the compression members eX- tending outwardly to the ends of the bolster.

3. A car truck bolster in which the tension member has a cross section including a flat bottom and curved sides adjacentthe end portions of the bolster and gradually uniformly merging into a semi-circle toward the center of the bolster, said tension member being coterminous with the bolster. i

4. A car truck bolster having a tension member formed with a convex under side, and

.a flat spring seatadjacent to'said convex HARRY w. STERTZBACH. 

